Drive lower units are back from paint. The Awlgrip paint we used on them actually turned better than expected. Also picked up the rams and small parts from polishing.

[ATTACH=CONFIG]560258[/ATTACH] [ATTACH=CONFIG]560259[/ATTACH] [ATTACH=CONFIG]560260[/ATTACH] [ATTACH=CONFIG]560263[/ATTACH]

Then to top off the week, I received a msg from a member who saw my post in another topic about a pair of very rare 2-spd trans. Just so happened he is doing a repower and is switching to crash boxes. I missed out on a set of these a couple months back, so this time I jumped in the truck and ran up to Michigan. Thanks Fight Club...

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What make are those? and what ratio?
They look nice compact units

1.50:1 low gear. Then a 1:1 locked up.

http://www.offshoreonly.com/forums/g...smissions.html

Tysons I see, is he using the same design in his new boat, difficult to determine on his build so far.
Should be perfect but these photos make them look longer, what's the overall length.

They have a Velvet Drive bolt pattern and are 12" long when bolted up.

Here is a graph of estimated boat speeds based on using a 1:16:1 final drive with a 35 pitch prop. You can see how that 1.50 low gear ratio brings rpms up in the sub 30mph range. My single GT4094 turbo boat started to spool good around 1400R with a 1:26:1 drive and 15"dia x 35 pitch. This planned drive and 1st gear ratio gives ya a 1.75 ratio out of the hole, then drops to a 1.16:1 once on plane. A good realistic starting point, with safe redline where the cams should be about done. .

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Hey Jay got a question right up your alley.. Does ZF and Borg Warner share same bolt pattern??

I'm trying to find an off the shelf SAE 3 adapter plate to fit these trans which have the Velvet drive bolt pattern. Not having much luck with that, but do see plenty of them for ZF 45A, 63A, 63IV and others. Sure looks the same, but haven't measured yet. Here is one I found.

http://www.fredwarner1.net/zf-marine...3-transmission

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Hey kid !
Far as i know the zf 63 Bolts right up to a merc bellhousing that Also fit the velvet so the answer is yes it does only thing that could be a issue is the distance to the coupler plate as the zf gearboxes have a longer input shaft then the velvet

Hope this helps

Thanks Bor, that's what I needed to know. Neither surface uses alignment pins, so that center whole size is critical. Google can't find a detailed drawing of the Velvet mounting face, but I'll bet ZF has it posted.

If I'm right the velvet / zf bolt pattern is called SAE 7

Sorry I am unable to help you here, my mountings are SAE 2, I never looked at any Velvet drive configurations as I couldn't find any of that style box in the correct ratio.
Also with me using Arnesons I needed to do the counter rotation in the gearbox and not in the drive, as far as I am aware the velvet drive style boxes can only run in one direction were as the ZF 305 I am able to run the same ratio and torque in forward or reverse.